Method for connecting at least one delivery duct to the muffler of a motor-compressor unit, and the motor-compressor unit obtained

Abstract

 A motor-compressor unit, in particular for refrigerators or the like, comprises a usual muffler (1) to which a fluid is fed through an intake duct and from which a delivery duct (7) extends.
To fix this latter to the muffler (1) it is inserted through a sleeve member (10). This latter is positioned within an aperture provided in the body (2) of the muffler (1), so that the sleeve member (10) adheres to the opposing walls (4, 5) of the edge (3) of said body (2) in which said aperture is provided.
The motor-compressor unit thus obtained comprises a delivery duct (17) inserted through a sleeve member (10) positioned within an aperture (6) in the body (2) of the muffler (1) so that its opposite ends (12, 13) project from said aperture (6), said sleeve member (10) comprising at each opposing mouth (6A, 6B) of said aperture (6) a collar (16, 19) which cooperates with the wall (4, 5) of the body (2) of the muffler (1).

Description

[0001] The present invention relates to a method for connecting at least one fluid delivery duct to the muffler of a motor-compressor unit, and the motor-compressor unit thus obtained.

[0002] In particular, the invention relates to a motor-compressor unit for refrigerators or the like.

[0003] As is known, the delivery duct is usually fixed to the muffler body by welding.

[0004] This obviously increases the construction time and cost of the motor-compressor unit with a corresponding increase in its selling price.

[0005] In addition, the welding operation, even if conducted very carefully, can damage both the duct and the muffler, and can also result in fluid leakage during its compression.

[0006] Other means of connecting the delivery duct to the muffler body are also known. These however are laborious in terms of their execution and sometimes result in a considerable increase in the muffler thickness following the duct connection.

[0007] An object of the invention is to provide a method for connecting the delivery duct to the muffler which is simple to implement and does not involve the aforesaid drawbacks of analogous known methods.

[0008] A further object is to provide a motor-compressor unit of the aforesaid type in which the connection between the duct and muffler can be made in a relatively short time, said connection not resulting in any possibility of fluid leakage from the muffler during its movement towards said duct.

[0009] A further object is to provide a motor-compressor unit in which the connection between the muffler and the duct can be made in a reliable and effective manner.

[0010] These and further objects which will be apparent to the expert of the art are attained by a method for connecting a delivery duct to a muffler in a motor-compressor unit, characterised by comprising inserting said duct through a sleeve member, positioning this latter within an aperture provided in the muffler body, said positioning being such that both the opposing ends of said sleeve member project from said aperture, and deforming said ends so as to obtain the adhesion of the sleeve member to the opposing walls of the edge of said body in which said aperture is provided.

[0011] Said method provides a motor-compressor unit comprising a muffler, an intake duct and a delivery duct for conveying a fluid for compression into the muffler body and for removing it from this latter respectively, characterised in that the delivery duct is inserted through a sleeve member positioned within an aperture in the muffler body so that its opposing ends project from said aperture, said sleeve member comprising at each opposing mouth or edge of said aperture a collar cooperating with that wall of the muffler body corresponding to said mouth so as to retain the duct secured to the muffler and to create a seal about it.

[0012] The present invention will be more apparent from the accompanying drawing, which is provided by way of non-limiting example and in which:

Figure 1 is a cross-section through part of a motor-compressor unit constructed in accordance with the invention;

Figure 2 is a section through that part of the motor-compressor unit shown in Figure 1 during a first stage in the execution of the method according to the invention; and

Figure 3 is a view similar to that of Figure 2 but during a different stage in the execution of the method according to the invention.

[0013] With reference to Figure 1, a motor-compressor unit, in particular for refrigerators, comprises a usual muffler 1 defined by a hollow body 2 having a perimetral edge 3 with an inner wall 4 and an outer wall 5.

[0014] In the edge 3 an aperture 6 is formed to contain a usual duct 7, this being specifically a delivery duct for the compressed fluid.

[0015] This duct comprises a wall 8 defining a passage 9.

[0016] According to the invention the duct 7 is inserted through a sleeve member 10 comprising a body 11 provided with opposing ends 12 and 13. This body is inserted through the aperture 6 so that it extends beyond its mouths 6A and 6B, into the body 2 of the muffler 1 and away from it respectively.

[0017] In proximity to that end 12 which projects into the body 2 of the muffler 1 there is provided a step 15 defining a collar 16 resting to form a seal against the inner wall 4 of said body at the mouth 6A of the aperture 6.

[0018] Likewise, in proximity to the end 13 of the sleeve member 10 (or simply sleeve) there are provided in succession a first step 17 and a second step 18. This latter defines a collar 19 resting to form a seal against the outer wall 5 of the body 2 at the mouth 6B of the aperture 6.

[0019] In addition, the body 11 of the sleeve 10 comprises a portion 11A positioned within said aperture 6. This portion tapers in passing from the mouth 6B to the mouth 6A of said aperture and is in sealed contact with the wall of this latter.

[0020] At said portion 11A of the sleeve 10 the duct 7 comprises a part 20 of reduced cross-section. This duct therefore assumes within the sleeve 10 a venturi tube formation which offers considerable obvious advantages during the use of the motor-compressor unit 1, these advantages deriving precisely from the shape of said duct 7.

[0021] The motor-compressor unit 1 and in particular the connection between the duct 7 and the muffler 2 are formed in accordance with the method of the invention, this method being described with reference to Figures 2 and 3. In these figures, parts corresponding to those of Figure 1 are indicated by the same reference numerals.

[0022] The first stage of forming the connection between the duct 7 and the muffler 2 (Figure 2) involves inserting the duct through the sleeve 10, after which the assembly formed is inserted through the aperture 6.

[0023] As can be seen the sleeve is substantially of frusto-conical shape so that during its insertion into the aperture 6 its body 11 fits with interference against the wall of this aperture.

[0024] Its insertion continues until the the body 11 projects from both mouths 6A and 6B of the aperture 6.

[0025] After this the sleeve 10 is deformed mechanically such that it assumes the described shape shown in Figure 1.

[0026] To achieve this, known pressing tools 30 and 40 are used, acting respectively on the opposing ends 12 and 13 of the sleeve 10.

[0027] The tools 30 and 40 comprise respective elongate holes 31 and 41 which receive the duct 7 and open into the faces 32 and 42 of said tools, these faces being arranged to cooperate with the corresponding ends 12 and 13 of the sleeve 10.

[0028] Said faces 32 and 42 are convex and concave respectively, and comprise flares 33 and 43 corresponding with the holes 31 and 41.

[0029] To allow proper engagement by the tool 40, the end 18 of the body 11 of the sleeve 10 is made slightly concave.

[0030] In addition, the flare 43 of the tool 40 connects to a cavity 44 into which the hole 41 opens, this hole having the same shape as the duct 7 but an obviously greater cross-section.

[0031] For the deformation of the sleeve 10 (represented in Figure 3), the tool 40 is applied to the end 13 of the sleeve 10 while at the same time the tool 30 is applied to the end 12 of this sleeve.

[0032] By now forcing the tools 30 and 40 together (ie pressing them towards the edge 3 of the muffler 1 in the direction of the arrows F and G), the sleeve 10 is deformed to obtain the shape shown in Figure 1.

[0033] During this operation the body 11 of the sleeve deforms to press against the duct 7. Specifically, the pressure on the portion 11A of this body modifies the shape of the part 20 of said duct, making it assume a venturi tube shape.

[0034] The deformation is complete when a step 45 provided between the cavity 44 and the hole 41 rests against the step 17.

[0035] During this deformation, collars 16 and 19 are created, positioned at the walls 4 and 5 of the edge 3 of the body 1.

[0036] The sleeve 10 is advantageously of rubber or a similarly plastically deformable material, so that the creation of the collars 16 and 19 and the deformation of its body 11 create a seal about the aperture 6 in the edge 3.

[0037] By this method a duct (the delivery duct) can be connected to the body of a muffler in a motor-compressor unit without using welding or mechanical operations which could damage the parts to be connected together or require additional machining of these parts to enable them to be connected together.

[0038] Furthermore, said method enables the connection to be obtained quickly and reliably.

Claims

1. A method for connecting a delivery duct to a muffler in a motor-compressor unit, characterised by comprising inserting said duct (7) through a sleeve member (10), positioning this latter within an aperture (6) provided in the body (2) of the muffler (1), said positioning being such that both the opposing ends of said sleeve member (10) project from said aperture, and deforming said ends (12, 13) so as to obtain the adhesion of the sleeve member (10) to the opposing walls (4, 5) of the edge (3) of said body (2) in which said aperture is provided.

2. A method as claimed in claim 1, characterised in that the deformation of the sleeve member (10) is achieved by pressing against the opposing ends (12, 13) in opposite directions.

3. A method as claimed in claim 1, characterised in that the deformation of the sleeve member (10) results in the contraction of a part (20) of the duct (7) contained in said sleeve member (10).

4. A motor-compressor unit obtained by the method claimed in claim 1, comprising a muffler (1), an intake duct and a delivery duct (7) for conveying a fluid for compression into a muffler body and for removing it from this latter respectively, characterised in that the delivery duct (7) is inserted through a sleeve member (10) positioned within an aperture (6) in the body (2) of the muffler (1) so that its opposing ends (12, 13) project from said aperture (6), said sleeve member (10) comprising at each opposing mouth or edge (6A, 6B) of said aperture (6) a collar (16, 19) cooperating with those walls (4, 5) of the body (2) of the muffler (1) corresponding with said mouth (6A, 6B) so as to retain the duct (7) secured to the muffler (1) and to create a seal about it.

5. A motor-compressor unit as claimed in claim 4, characterised in that that part (20) of the duct (7) contained within the sleeve member (10) is of venturi tube shape.

6. A motor-compressor unit as claimed in claim 4, characterised in that the portion (11A) of the body (11) of the sleeve member (10) is inserted with an interference fit into the aperture (6) in the body (2) of the muffler (1) and cooperates in a sealed manner with the wall of said aperture (6).

7. A motor-compressor unit as claimed in claim 4, characterised in that the collars (16, 19) of the sleeve member (10) cooperate in a sealed manner with the walls (4, 5) of the body (2) of the muffler (1).

Drawing